JPS6290998A - Photosetting resist resin compound for nonelectrolytic plating - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photocurable resist resin composition, and more particularly, the present invention relates to a photocurable resist resin composition having improved plating liquid resistance properties for use in electroless plating, particularly for screen printing. The present invention relates to a photocurable resist resin composition that has been passed through.

The resist film made of the photocurable resist resin composition for electroless plating of the present invention has not only the meso-resist performance but also the chemical resistance, solvent resistance, solder heat resistance, and electrical properties required in the meso-resist process and thereafter, as a permanent resist. Has excellent performance.

Therefore, the photocurable resist resin composition for electroless plating of the present invention can be used particularly as a resist for electroless plating in the full-additive method or the part-additive method for manufacturing printed wiring boards, which has been put into practical use in recent years. Not only can it be suitably used for forming a film, but it can also be used for forming a protective resist for wiring boards.

[Prior art]

BACKGROUND ART Conventionally, a method for manufacturing printed wiring boards in which a conductor circuit is formed on an insulating board only by electroless plating is known as a full additive method. Furthermore, a method for manufacturing printed wiring boards has recently been introduced as a part-additive method, in which a conductor circuit is formed by etching a copper-clad laminate, and then the through-hole portions are plated using only electroless plating.

These methods simplify the manufacturing process for manufacturing double-sided through-hole boards compared to the so-called subtract method, which is well known as the most common method for manufacturing printed wiring boards. It is suitable for manufacturing relatively high-density printed wiring boards using inexpensive substrate materials such as substrates.

Therefore, in recent years, the full additive method or the partially additive method has been increasingly adopted as a method for manufacturing printed wiring boards.

However, in the full additive method and the part-additive method (hereinafter collectively referred to as the "additive method"), the plating time is longer than that of through-hole conductive plating, which uses both electroless plating and electrolytic plating used in the subtract method. In addition, the formed resist is not a temporary resist (it is used as a permanent resist, so in addition to the plating liquid resistance, it also has the chemical resistance, solvent resistance, and It is required to have properties as an electrically insulating material that has solder heat resistance, as well as heat resistance and moisture resistance required in the environment in which printed wiring boards are used.

In other words, Menki resist for the additive method can be used at high temperatures,
It is required to have both the performance as a plating resist that can withstand severe coating conditions such as immersion in a high pH plating bath for a long time, and the performance of a permanent resist required for a solder resist.

Examples of resist resins that satisfy these strict characteristics include JP-A-54-13574 and JP-A-58-939.
Thermosetting epoxy resin-based electroless mesochrecyst ink disclosed in publications such as No. 8 and JP-A No. 59-117196 is generally known, and is commercially available as a commercially available product manufactured by Tokyo Ohka Kogyo ■. There is NT-30.

On the other hand, as a commercially available UV-curable resist ink,
Kaney Yoshikawa has introduced UV-curable permanent mask inks PPP-101 and PPP-102A manufactured by American PCK Corporation for use in the additive method, but their composition has not been disclosed.

UV-curable solder resist inks are widely used mainly for consumer printed wiring boards.

Currently, commercially available ultraviolet curable solder resist inks are mainly composed of prepolymers of bisphenol A type epoxy acrylate and novolac type epoxy acrylate.

Furthermore, as an epoxy acrylate-based ultraviolet curable solder resist ink, Japanese Patent Application Laid-Open No. 59-51962,
JP-A-59-89316, JP-A-59-126473
No., JP-A-59-213779, JP-A-59-213
Patent applications such as No. 780 have been filed.

Further, recently, the development of urethane acrylate-based photocurable resins has become active, and many patent applications have been filed even if the use is limited to printed wiring boards. For example,
5-23479, JP 55-58226, JP 57-3875, JP 57-78414, JP 57-78415, JP 59-120613, JP 59-23723 etc. have been published.

[Problem that the invention seeks to solve]

The main characteristics of resists for electroless plating for additive methods are that the resist film is left in a high temperature (e.g. 65 to 74°C), strongly alkaline (pH 12.0 to 13.5) plating bath for a long period of time (10 to 13.5 degrees Celsius). 30 hours), there is no deterioration of the resist film, no elution of resin components into the plating bath, no abnormal precipitation of plating on the resist, and the chemical resistance and solvent resistance required after the plating process. It is required to have sufficient properties such as solder heat resistance and electrical properties after a solder heat resistance test and a moisture resistance test.

The above-mentioned epoxy-based thermosetting resist ink has excellent resist performance, but it takes a long time to cure, and the printed ink inevitably flows when heated and dried, so it is difficult to print a circuit with a thick film and high resolution. It was difficult to obtain a pattern.

The commercial products introduced as UV-curable resist inks have problems with printing suitability such as internal curing during thick film curing, smoothness of printed coatings, gloss, pinholes, and resolution. The insulation resistance value after plating and moisture resistance test is inferior to that of the thermosetting type, so it is not always satisfactory.

Epoxy acrylate-based UV-curable solder resist ink can be used as a solder resist ink, but if it is immersed in a high-temperature, high-pH plating bath for a long time, uncured monomer components may be eluted into the plating bath. The plating bath is contaminated, probably due to hydrolysis of the ester group, and the resist film is deteriorated by the plating solution, resulting in a decrease in solder heat resistance and electrical insulation properties. It is not something that can withstand.

None of the patent publications for the urethane acrylate-based photocurable resins clearly state that they can withstand the conditions of use as an insulating protective film for printed wiring boards or as a solder resist (ink or dry film). However, it has not been considered as a resist for electroless plating for additive methods.

As mentioned above, thermosetting type resist inks for electroless plating for additive methods have been developed that are sufficiently practical, but they require a long time to cure, and they require a thick thickness with good printing resolution. There was a problem that it was difficult to obtain a film resist pattern.

On the other hand, although ultraviolet curing type has the potential to shorten curing time and improve resolution, it does not practically satisfy the performance required for electroless plating resists for additive methods, especially plating liquid resistance. has not yet been developed.

The present invention solves the problems of the prior art described above and has sufficient characteristics as an electroless metsukiresist for additive methods, which has excellent fast curing properties, thick film curing properties, and thick film resolution, especially for screen printing. The object is to provide a photocurable resist resin composition suitable for use as an ink.

[Means for solving problems]

As a result of intensive studies to achieve the above object, the present inventors have found that by using a resin composition having a specific urethane acrylate oligomer as its main skeleton, various resists can be used as an electroless plating resist for additive methods. The inventors discovered that a resist film satisfying the required performance could be obtained and completed the present invention.

The present invention provides (1) a photocurable resist resin composition for electroless plating containing the following components (A), (B) and (C).

(8) (a) At least two polyols selected from the group consisting of polyether polyols and polyols having urethane bonds (bl) Non-yellowing polyisocyanate (Cl) General formulas (a), (b) and ( C) obtained by reacting
A urethane (meth)acrylate oligomer having a number average molecular weight of 500 to 3000 and a (meth)acryloyl equivalent of 200 to 800, or selected from the group consisting of polyether polyols, polyester polyols, and polyols having urethane bonds. A number average molecular weight of 500 to 3000 obtained by reacting at least one polyol with the above (bl non-yellowing type polyisocyanate and (C) acrylic compound,
and a mixed urethane (meth)acrylate oligomer of at least two types of urethane (meth)acrylate oligomers having a (meth)acryloyl equivalent of 200 to 800 having different polyol components (B) a photocurable compound containing a difunctional acrylic monomer; The reactive diluent (C) is a photopolymerization initiator.

In the present invention, the urethane (meth)acrylate oligomer of component (A) has a number average molecular weight of 500 to 3000.
, and the (meth)acryloyl equivalent is 200 to 800
It is obtained by reacting a (meth)acrylic compound (Cl) with a urethane prepolymer consisting of a specific polyol component (al and a non-yellowing type polyisocyanate component).

The cured product of the urethane (meth)acrylate oligomer of component (A) is prepared using a high temperature, high p)I electroless method. It has properties suitable for a resist resin for electroless plating, having both the performance of a Menki resist that can withstand the severe plating conditions of long-time immersion in a 7-ki bath and the performance of a permanent resist required for a solder resist.

If the number average molecular weight of the urethane (meth)acrylate oligomer of component (8) is less than 500, the viscosity of the target composition will be too low, making it difficult to obtain good printability when formed into an ink, and causing various problems with the coating film. The physical properties are unbalanced and the plating liquid resistance is lacking.

On the other hand, if the number average molecular weight is greater than 3000, the viscosity of the target composition will increase, workability will decrease, and it will be necessary to add a large amount of reactive diluent.

Furthermore, the crosslinking density of the cured product decreases, and the solvent resistance, chemical resistance, plating liquid resistance, etc. are greatly decreased, and the performance as a resist for electroless plating cannot be maintained.

When the (meth)acryloyl equivalent of the urethane (meth)acrylate oligomer of component (8) is less than 200,
The cured product has a high crosslinking density and a coating film with excellent performance is obtained, but uncured (meth)acryloyl groups remain in the cured product, and the uncured product gets into the plating solution during plating work. Not only will it be extracted and cause contamination of the plating solution, but
The storage stability of the composition is extremely low.

On the other hand, if the (meth)acryloyl equivalent is greater than 800, the photoactivity of the composition will decrease, and the cured product will be insufficiently cured due to a decrease in crosslink density, resulting in decreased solvent resistance, chemical resistance, etc., and plating. During the work, the coating deteriorates and cannot maintain its performance as mesochyrecyst.

The polyol component (a) used as a raw material for the synthesis of the urethane (meth)acrylate oligomer of component (A) has a main chain skeleton selected from a wide range of polyether polyols, polyester polyols, and polyols having urethane bonds. It is a mixture of at least two different polyols.

When only polyether polyol is used as the polyol component (al), a resist film with good plating liquid resistance can be obtained, but a drawback is recognized in the coating film performance as a permanent resist. A polyester polyol or a polyol having a urethane bond can be added to the polyol component (a) in an amount of 1 to 60 parts by weight.

Further, instead of the mixture of polyether polyol and polyester polyol, polyether polyester polyol can also be used.

The mixing ratio of polyol component (a) is polyether polyol/polyester polyol-9
9 to 40 parts by weight / 1 to 60 parts by weight Polyether polyol / Polyol having urethane bonds - 99 to 40 parts by weight / 1 to 60 parts by weight Polyester polyol / Polyol having urethane bonds - 1 to 60 parts by weight / 99 ~40
It is desirable that the amount is within the range of parts by weight.

If the mixing ratio of the polyester polyol component becomes excessive, the content of the polyester portion of the urethane (meth)acrylate oligomer increases, which is not preferable because the plating solution resistance to a strongly alkaline electroless plating solution decreases.

The present invention is characterized by containing at least two of the above-selected polyol components, and the polyol components include acrylic polyol, polybutadiene polyol, epoxy polyol, epoxy-modified polyol 1 polycarbonate polyol, polyhydroxyalkane. It is also possible to improve the physical properties of the urethane (meth)acrylate oligomer by adding and using oil-modified polyols, castor oil-modified polyols, etc. within a range of 10 parts by weight or less to the above-mentioned polyol component (81,100 parts by weight).

The polyols used in the present invention are illustrated below.

(i) Polyether polyol Ethylene oxide, propylene oxide.

trimethylene oxide, butylene oxide.

α-methyltrimethylene oxide, 3,3°-dimethyltrimethylene oxide, tetrahydrofuran.

Polyether glycols and polyoxyalkylene glycols obtained by ring-opening polymerization or copolymerization of alkylene oxides such as dioxane, styrene oxide, epichlorohydrin, phenylglycidyl ether, and allylglycidyl ether in the presence of a catalyst such as boron trifluoride. Examples include polyether polyols called.

Polyether polyols such as polypropylene glycol and polyethylene glycol are preferably used.

(11) Polyester polyol Ethylene glycol, diethylene glycol.

Triethylene glycol, propylene glycol.

dipropylene glycol, tripropylene glycol,
Butylene gelicol, hexylene glycol, neopentyl glycol, cyclohexane dimetatool, polyethylene glycol, polyoxypropylene glycol,
Polyhydric alcohols represented by diols, triols, and hexaols such as polyoxybutylene glycol, glycerol, trimethylolpropane, pentaerythritol, and sorbitol, and succinic acid, adipic acid, azelaic acid, sebacic acid, and oxalic acid. Saturated fatty acids such as; unsaturated fatty acids such as maleic acid and fumaric acid; phthalic acid,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
Aromatic fatty acids such as hexahydrophthalic acid; polyester polyols obtained by reaction with dicarboxylic acids represented by, or ring-opening copolymerization of intramolecular ester lactones such as caprolactone and methylcaprolactone with glycol, etc. can be mentioned.

(iii) Polyurethane polyol Examples include polyurethane polyols obtained by reacting polyols such as polyhydric alcohols, polyether polyols, and polyester polyols shown in items (i) and (ii) above with polyisocyanates shown below. .

Useful polyisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate,
2.6-Diisocyanate methyl proate 3-Isocyanate methyl-3,5,5,trimethylcyclohexyl isocyanate, 4,4''-methylenebis(cyclohexyl isocyanate).

Monomers and trimers of 1.3- or 1.4-bis(isocyanatomethyl)cyclohexane, methylcyclohexane-2,4-diisocyanate, m- or p-phenylene diisocyanate, diphenylmethane 4,4'-diisocyanate, isophorone diisocyanate , 1.3- or 1.4-xylylene diisocyanate monomers or polymers, which may be used alone or as a mixture.

Preferred polyisocyanates include alicyclic polyisocyanates such as monomers and trimers of 4.4 methylene biscyclohexyl isocyanate, C4-cyclohexylxylene diisocyanate, and isophorone diisocyanate.

Non-yellowing polyisocyanate components (bl) include polyisocyanate monomers or polymers selected from a wide range of polyisocyanates, used alone or in mixtures.

The non-yellowing polyisocyanate (b) is an alicyclic polyisocyanate, such as 4,4-methylenebiscyclohexyl diisocyanate.

1.4-cyclohexylxylene diisocyanate.

Cyclohexylene (4-isocyantophenyl)methane diisocyanate, isophorone diisocyanate monomer and trimer, 1-ω-methylisocyanate-2-
ω-n-propylisocyanate-3,5-dimethylcyclohexane: aliphatic polyisocyanate having a cyclic group, such as 1,4-xylene diisocyanate 1,
2-Xylene diisocyanate 1,4-diethylpenzole diisocyanate, 1,4-dimethylnaphthalene diisocyanate, ω-ω“-diisocyanate-n-propyl-biphenyl: Aliphatic polyisocyanates, such as dimethylene diisocyanate, propane diisocyanate, butene diisocyanate Tetramethylene diisocyanate, thiodiethyl diisocyanate-1-.

Pentane diisocyanate, β-methylbutane diisocyanate, hexamethylene diisocyanate, thiocypropyl diisocyanate, heptane diisocyanate,
2.2-dimethylpentane diisocyanate 3-
Methoxyhexane diisocyanate, octamethylene diisocyanate, 2,2°4-trimethylpentane diisocyanate, nonane diisocyanate, 1-decane diisocyanate, 3-butoxyhexane diisocyanate, undecane diisocyanate, thiodihexyl diisocyanate, and the like can be used.

In particular, alicyclic isocyanates such as monomers and trimers of 4,4-methylenebiscyclohexyl diisocyanate, 1,4-cyclohexylxylene diisocyanate, and isophorone diisocyanate are preferably used.

Acrylic compound (C1 is a compound represented by the following general formula % formula % (where R is hydrogen or a methyl group, and R represents an alkylene or oxyalkylene residue having 2 to 5 carbon atoms). be.

For example, 2-hydroxyethyl metafurerate, 2
-Hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate,
2-hydroxybutyl acrylate, 2-hydroxypentyl methacrylate.

Examples include hydroxy (meth)acrylate a such as 2-hydroxypentyl acrylate, which may be used alone or in combination of two or more.

The use of hydroxy (meth)acrylate having 6 or more carbon atoms represented by the general formula above causes a large increase in the viscosity of the reaction product during the synthesis reaction of the urethane (meth)acrylate oligomer of component (8), and it is difficult to use solvent-free solvents. This is not preferred because the reaction in the system becomes difficult and the desired component (A) cannot be synthesized.

The urethane (meth)acrylate oligomer of component (A) can be synthesized by the following method.

A urethane prepolymer is synthesized by reacting the mixture of the polyols (al) and non-yellowing type polyisocyanate bl, and then reacting the obtained urethane prepolymer with an acrylic compound (C1).

The urethane prepolymer is synthesized by reacting 0.8 to 1.2 mol of the non-yellowing polyisocyanate (b) with 1 equivalent of the functional group of the polyol (a).

If the reaction molar ratio is outside the above range, gelation will occur very easily, which is not preferable.

The reaction is carried out at a temperature of 25-100°C for at least 30 minutes, but it is generally preferred to carry out the reaction at a temperature of 40-80'C for about 2 hours.

If the reaction temperature is too low, the reaction will take a long time.

Further, a reaction temperature higher than 100° C. is not preferred because a reaction product with an inappropriately high viscosity is obtained.

The urethane prepolymer obtained by the above method has the same number of isocyanate groups as the number of active hydrogens of the polyol having functional groups.

In the reaction between an isocyanate group and a hydroxyl group, usually
Urethane reaction catalysts such as tertiary amines and organometallic compounds are used, but in order to use the reaction product as a photocurable resist for electroless plating, the reaction should be performed with as little or no catalyst added as possible. This is desirable.

Next, to the urethane prepolymer obtained by the above method,
The above acrylic compound (C) is reacted.

The reaction between the urethane prepolymer and the acrylic compound is usually carried out at a temperature of 25 to 100°C for 30 minutes, but it is preferably carried out at a temperature of 80°C for about 4 hours, and air is kept in the reaction vessel. It is preferable to react while blowing in order to prevent gelation and thickening.

The reaction ratio between urethane prepolymer and acrylic compound is
0.8 to 1.2 equivalents of hydroxyl groups in the acrylic compound are suitable for 1 equivalent of isocyanate groups in the urethane prepolymer; if the amount is less than 0.8 equivalents, the photocurability of the resulting resin will decrease; If the amount exceeds 2 equivalents, the properties of the cured product will deteriorate.

By the above method, polyol (a), polyisocyan name-1
The urethane (meth)acrylate oligomer of component (A) can be synthesized by reacting -(bl and the acrylic compound (C)).

In addition, if the compatibility of at least two polyols selected from the group consisting of polyether polyols, polyester polyols, and polyols having urethane bonds used as polyol (a) is poor, and it is impossible to mix them, control during the reaction may be necessary. When the desired urethane prepolymer cannot be obtained, such as when it is difficult to obtain the desired urethane prepolymer and an increase in viscosity is observed, the urethane (meth)acrylate oligomer of component (A) can be synthesized by the following method.

Pour polyisocyanate+-tb+ into the reactor and heat from 30 to
The mixture is heated to 80° C., and then an acrylic compound (C) is added dropwise to synthesize a blocked isocyanate compound in which a portion of the isocyanate groups are blocked. As for the synthesis conditions for the blocked isocyanate, it is desirable to react at a temperature of 60° C. or lower for about 2 hours.

Furthermore, the desired urethane (meth)acrylate oligomer of component (8) can be synthesized by reacting the obtained blocked isocyanate and polyol (al) according to the method for synthesizing the urethane prepolymer described above. can.

In the present invention, in place of the urethane (meth)acrylate oligomer of component (A) synthesized using the mixed polyol as a raw material, the synthesis method uses the polyether polyol, polyester polyol, or polyol containing urethane bonds alone as a raw material. Under the same conditions as
After synthesizing each urethane (meth)acrylate oligomer with a number average molecular weight of 500 to 3,000 and a (meth)acryloyl photometer of 200 to 800, polyols with different polyol components are mixed so as to have a desired mixing ratio of the polyol components. A mixed urethane (meth)acrylate oligomer mixed with can be used as component (8).

Furthermore, a polymerization inhibitor (stabilizer) is used to prevent early crosslinking during urethane (meth)acrylate synthesis and storage.

Examples of these are: di-t-butyl-p-cresol, hydroquinone methyl ether, pyrogallol, quinone.

Hydroquinone, t-butylcatechol, hydroquinone monobenzyl ether, methylhydroquinone, amylquinone, phenol, hydroquinone monopropyl ether, phenothiazine, nitrobenzene, etc. are preferably added singly or as a mixture of two or more.

The amount of polymerization inhibitor used is o, oos~ based on the total resin content.
0.5% by weight, preferably 0.01-0.05% by weight.

In the present invention, component (B), a photocurable reactive diluent containing a bifunctional acrylic monomer, is used for viscosity adjustment.

That is, the viscosity of the composition is 50 to 800P/25°C,
Preferably, the temperature is adjusted to 80 to 500P/25°C.

As a reactive diluent for this purpose, a reactive diluent containing a bifunctional acrylic monomer having a boiling point of 180° C. or higher at normal pressure is preferably used for screen printing inks.

Representative bifunctional acrylic monomer compounds of component (B) include, for example, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and ethylene glycol di(meth)acrylate.

Diethylene glycol di(meth)acrylate Triethylene glycol di(meth)acrylate.

Tetraethylene glycol di(meth)acrylate Propylene glycol di(meth)acrylate, dibrobylene glycol di(meth)acrylate Tripropylene glycol di(meth)acrylate 1,3-butylene glycol di(meth)acrylate, 1,4-butylene Examples include glycol di(meth)acrylate, 1,6-hexanethiol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and the like.

The amount of the reactive diluent used as component (B) is 10 to 70 parts by weight per 100 parts by weight of the urethane (meth)acrylate oligomer as component (^), and the viscosity range of the target composition is adjusted to the above range. It is desirable to make the minimum amount necessary to adjust.

Further, these bifunctional acrylic monomers can be used in combination with monofunctional acrylic monomers and trifunctional or higher functional acrylic monomers.

Typical monofunctional acrylic monomers include butyl (meth)acrylate, cyclohexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate.
Acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, hexyl diglycol (meth)acrylate, ethyl carpitol (meth)acrylate 3 (
Methyl triglycol acrylate, tetrahydrofurfuryl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate ) Acrylate Methoxytriethylene glycol (meth)acrylate etc. can be used.

In addition, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolethanetri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, dipentaerythritol pentaacrylate, trimethylolpropane tri(meth)acrylate, trimethylolmethanetetra(meth)acrylate, dipentaerythritolpentaacrylate, etc. (meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. can be used.

In the present invention, the photopolymerization initiator as component (C) is a photocurable reactive diluent containing the urethane (meth)acrylate oligomer as component (8) and/or the bifunctional acrylic monomer as component (B). There is no particular limitation as long as it can be activated by light irradiation.

Typical photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin acetate, benzophenone, 2-chlorobenzophenone, 4-methoxybenzophenone, 4.
4'-dimethylbenzophenone, 4-bromobenzophenone, 2.2',4.4"-tetrachlorobenzophenone, 2-chloro-4'-methylbenzophenone,
3-Methylbenzophenone, 4-L-butylbenzophenone, benzyl, benzylic acid, benzyl dimethyl ketal, diacetyl, methylene blue, acetophenone, 2,2°-jethoxyacetophenone, 9.10-
phenanthrenequinone, 2-methylanthraquinone,
Examples include 2-ethylanthraquinone, 2-t-butylanthraquinone, diphenylsulfisode, dithiocarbamate, α-chloromethylnaphthalene, anthracene, iron chloride, and 1,4-naphthoquinone.

In particular, 2,2-jethoxyacetophenone 12,2-dimethoxy-2-phenylacetophenone, benzoin isopropyl ether, benzoin isobutyl ether,
2-ethylanthraquinone, thioxanthone, benzyl dimethyl ketal and the like are preferably used.

These photopolymerization initiators may be used alone or in combination of two or more.

The amount of photopolymerization initiator used is approximately 0.05% based on the total resin content.
-10% by weight, preferably 0.1-5% by weight.

Furthermore, it is advantageous to use amines, thiols, etc. as a photopolymerization accelerator in combination with a photopolymerization initiator, since the curing rate is increased and the polymerization inhibiting effect of oxygen and the like is significantly suppressed.

These photopolymerization accelerators may be used alone or in combination of two or more.

In particular, 1,000-ol compounds containing at least one thiol group per molecule are preferably used because the polymerization inhibiting effect of oxygen is significantly suppressed.

On the other hand, amines cannot be used because they form a complex with the electroless plating solution, impair the stability of the plating bath, and deteriorate the physical properties of the sinus coating.

The amount of photopolymerization accelerator used is approximately 0.01 based on the total resin content.
-6% by weight, preferably 0.03-4% by weight.

Further, if necessary, it is also possible to use a radical polymerization initiator represented by peroxide and a radical polymerization promoter represented by metal soaps in combination with a photopolymerization initiator to perform crosslinking by combined heat curing.

In the present invention, the components (Δ), (B) and (C)
In order to create a photocurable resin composition that has sufficient properties as a resist for electroless plating for additive methods and is particularly suitable for use as a screen printing ink,
Various additives can be added as necessary.

These additives include fillers, pigments and dyes.

Viscosity modifiers, leveling agents, plasticizers, various polymer substances,
Examples include various additives such as antifoaming agents, polishing agents, coupling agents, surfactants and other auxiliary agents, modifiers, and solvents.

The amount of these additives to be used varies depending on the use, purpose, and method of use, but it is preferably at most 200 parts by weight or less, preferably 100 parts by weight or less, based on 100 parts by weight of the total resin content.

The additives mentioned above are used depending on the purpose.

Fillers include, for example, lipophilic silica, bentonite, silica powder glass, etc., which can preferably be used in particles with a particle size of up to several microns.

Pigments for coloring include extender pigments such as alumina white, clay, talc, barium sulfate, barium carbonate, zinc white, lead white, yellow lead, red lead 5 ultramarine, deep blue, titanium oxide, zinc chromate, red iron, Inorganic pigments such as carbon black, Brilliant Carmino 6B, Permanent Red R,
Examples include organic pigments such as benzidine yellow, phthalocyanine blue, and phthalocyanine green.

Examples of dyes include basic dyes such as magenta and rhodamine, direct dyes such as Direct Scareso, Direct Orange, and acidic dyes such as Roserin and Methanil Yellow.

Hentonite, silica gel as a viscosity modifier.

Examples include aluminum and oftate.

In addition, plasticizers lower the initial viscosity of the resin, facilitate the incorporation of fillers, and provide elasticity to the coating film. Leveling agents, antifoaming agents, surfactants, coupling agents, etc.
Used to improve the printability of ink.

These various additives are used to impart performance as a resist ink, and can be used in the same manner as those used in the -II resist ink.

On the other hand, solvents are used in liquid photoresists or thermosetting resist inks, and generally various solvents belonging to the ketone, alcohol, ester, ether, aliphatic or aromatic hydrocarbon types are used. Can be used.

As shown above, the present invention further provides a resin composition containing as essential components a urethane (meth)acrylate oligomer (A) component, a photocurable reactive diluent (B) component, and a photopolymerization initiator. Depending on the application, various additives, modifiers and solvents are mixed and used as a resist ink.

As described above, the photocurable resist resin composition for electroless plating of the present invention contains a urethane (meth)acrylate oligomer as component (A) and a bifunctional acrylic monomer as component (B). Sex diluents and ingredients (C
) It is characterized by containing a photopolymerization initiator as an essential component, and is put to practical use in the form of resist ink or liquid photoresist.

When used as Menki resist ink, the ingredients (
Since the urethane (meth)acrylate oligomer A) has a high viscosity, a photocurable reactive diluent as component (B) is added to adjust the viscosity, and a photocurable reactive diluent as component (C) is added to initiate polymerization. It is used in a system containing a polymerization initiator and various additives for printing ink.

On the other hand, when used as a liquid photoresist, an organic solvent is further added to the above composition to adjust the viscosity before use.

In addition, when using an off-contact type exposure device,
It is also possible to use compositions that are the same as or similar to those prepared for inks.

A specific method of using the photocurable resist resin composition for electroless plating of the present invention, particularly a formulation as a screen ink, will be described in detail below.

In the image forming method by screen printing, the resin composition is adjusted to an ink having thixotropic properties,
An image is formed on the substrate by screen printing. Next, by irradiating ultraviolet rays to cure and crosslink, the drawn Menki resist film is formed on the substrate.

The ink consists of a urethane (meth)acrylate oligomer as a component (A), a reactive diluent as a component (B), and a component (
Blend the photopolymerization initiator in C), mix well, and reduce the viscosity to 50.
Adjust to ~500P/25℃.

Next, pigments, fillers, leveling agents, antifoaming agents, etc. are added, and the mixture is kneaded using a Miki roll.

The screen used for image formation is preferably one made of stainless steel, polyester, silk, etc., with a mesh size of 150 to 300 mesh.

As the ultraviolet irradiation light source, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, etc. that emit light in a wavelength range of 200 to 500 nm that can activate a photopolymerization initiator and a photopolymerization accelerator are used.

Further, the liquid composition whose viscosity has been adjusted can be used as a liquid photoresist using a photographic image forming method.

[For production]

The photocurable resist resin composition for electroless plating of the present invention has excellent fast curing properties, thick film curing properties, and thick film resolution. Even when immersed for a long time, there is no deterioration of the resist film or adverse effects on the plating bath, and no abnormal plating precipitation is observed on the resist film, making it an excellent resist for electroless plating for additive methods. has.

Furthermore, in the manufacture of printed wiring boards, the resist film sufficiently satisfies the chemical resistance, solvent resistance, solder heat resistance, and electrical properties after the solder heat resistance test and moisture resistance test required after the plating process.

Although it is not clear how the resin composition affects these properties, the selection of the urethane (meth)acrylate oligomer as component (A) in particular makes a large contribution.

〔Example〕

The present invention will be specifically explained with reference to Examples.

However, the scope of the present invention is not limited in any way by the following examples.

All parts and percentages in the following examples are by weight unless otherwise specified.

(11 Synthesis of one type of urethane (meth)acrylate oligomer constituting component (A) or urethane (meth)acrylate oligomer of component (A): Sample (A-1) Polypropylene glycol with a molecular weight of 400; 423 parts and isophorone diisocyanate ; 440 parts were charged into a reaction vessel equipped with a stirrer, a nitrogen gas blowing tube, a thermometer, a reflux condenser, and a dropping funnel, and after nitrogen substitution, the mixture was gradually heated to a temperature of 80°C while stirring. The mixture was kept for 3 hours to react.

The reaction product obtained is a clear solution containing free isocyanate 2
It was a diisocyanate compound containing 9.5% of -1-.

Next, 232 parts of 2-hydroxyethyl acrylate was added dropwise from the dropping funnel over a period of 2 hours while blowing a small amount of nitrogen gas into dry air. After the dropwise addition is complete, keep the temperature at 80°C and continue the reaction for 3 hours! ! Subsequently, the reaction was completed to obtain a urethane (meth)acrylate oligomer (A-1) constituting component (A).

The reaction product obtained was free isocyanate; 0.1%
The following was a viscous oligomer of acryloyl 31,538.

Samples (A-2) to (A-8) Under the same reaction conditions as Sample (A-1), the type, combination and By changing the reaction amount, one type of urethane (meth)acrylate oligomer constituting component (A) shown in Table 1 or the urethane (meth)acrylate oligomer (8-2) to (8-2) of component (A)
A-8) was synthesized.

Sample (A-9) 296 parts of isophorone diisocyanate was charged into a reaction vessel under nitrogen substitution, and 156 parts of 2-hydroxyethyl acrylate was added dropwise from the dropping funnel over 1 hour.

The reaction was further maintained at a temperature of 60 to 80°C for 2 hours to complete the reaction.

The synthesized blocked isocyanate compound contained 12.2% free isocyanate.

Next, an adipic acid polyester with a hydroxyl equivalent of 63 (
A compound synthesized with a charging ratio of adipic acid/diethylene glycol/trimethylolpropane-100/72.715.6); 300 parts, molecular weight: 700 polypropylene glycol; 71 parts and the previously synthesized monoisocyanate compound, 80 parts The urethane acrylate oligomer (A-
9) was obtained.

The obtained urethane acrylate oligomer (A-9) contained 0.05% or less of free isocyanate and had an acryloyl equivalent of 618.

Samples (A-10) to (A-13) Urethane acrylate oligomer (A-10) of component (8) shown in Table 1 was synthesized under the same synthesis conditions as sample (^-9).
) to (A-13) were synthesized.

Comparative samples (A-14) to (A-20) Samples (A-
Urethane (meth)acrylate oligomers (A-14) to (A-20) for comparison shown in Table 1 were synthesized according to the synthesis methods of Example 1) and Sample (A-9).

Synthesized urethane (meth)acrylate oligomer (A
-1) to (A-20) are summarized in Table 1.

(2) Preparation of photocurable resist resin composition for electroless plating: Samples (R-1) to (11-16) Urethane (meth)acrylate oligomer synthesized in the above item (1) (A-1) to After reducing the viscosity of (A-13) alone or in a mixture of two to 100 to 500 P/25°C using a photocurable reactive diluent as component (R),
The photopolymerization initiator of component (C), phthalocyanine blue, an antifoaming agent, a leveling agent, thixotropic 4-grit, etc. were blended and kneaded using a roll mill to obtain the composition of the present invention having the composition shown in Table 2. The photocurable resist resin compositions (R-1) to (R-19) for electroless metal plating were prepared three times.

Comparative samples (CR-1) to (CR-7) Among the urethane (meth)acrylate oligomers synthesized in section tl), comparative samples (A-14) to (8-2)
0) alone in the samples (R-1) to ([?-16
), and a comparative resin composition (CR-1
) to (CR-”I) were adjusted.

Comparative samples (CR-8) to (CR-9) Resist inks for electroless plating containing commercially available epoxy resin as the main component (PPP-101 and PPR-1028:
Yoshikawa Kako@Sales) were used as photocurable resin compositions (CR-8) to (CR-9) for comparison.

Table 2 shows the blending compositions of the prepared resin compositions; samples (R-1) to (R-16) and comparative samples (CR-1) to (c)'l-7).

(3) Preparation of test specimens: The prepared samples and comparative samples were preliminary kneaded using a Raikai machine, and then kneaded using three rolls to form ink.

On the other hand, apply nitrile rubber Evergreep 777 (manufactured by Sale Chilny Co., Ltd., trade name) as an adhesive on the cleaned glass-epoxy substrate (FR-4 equivalent) or the above substrate.
A substrate with an adhesive coated to a thickness of 0 μm and heat-cured at 180° C. for 30 minutes was prepared as a substrate material.

The ink-formed preparation sample and comparative sample were coated onto this substrate using screen printing or a bar coater so that the film thickness was 25 to 35 μm.

Then, LOc was applied using a high-pressure mercury lamp (80W/cm).
Light irradiation was performed from a distance of m for a predetermined period of time to obtain a cured coating film.

(4) Electroless plating test The adhesive-attached substrate shown above was activated for electroless steel plating by the following method.

Chromic acid; 300g/l and sulfuric acid; 200g/e
The substrate was immersed in the mixed solution and kept at 60° C. for 15 minutes to roughen the surface, and then washed with water, followed by a catalyst solution (palladium chloride concentration: 0. 2g-PdC(!2/l-)
After dipping at 50°C for 1 minute, soaking at 50°C for 1 minute
%H2SO4 solution for 10 minutes to perform a disproportionation reaction of the mixed colloid to metallize it, and then Pd catalyst treatment was performed.

The prepared ink was applied onto the activated substrate and cured by irradiation with light to form a resist for electroless plating.

A substrate (test body) on which a resist for electroless plating was formed was immersed in a copper plating solution having the following composition, and copper plating was performed.

The electroless copper plating solution composition was adjusted with reference to Japanese Patent Publication No. 5B-50040.

Sulfuric acid 1 hour 10g
/ 1 (0.04mol/ff) ethylenediaminetetraacetic acid tetrasodium 30g / II! (0,08
mol/E) 37% formalin solution 3m2
/ β polyethylene glycol (PEG 600) 100 mg / 1-2
．． 2"-dipyridyl 20 mg/t! Sodium hydroxide Amount of water to reach pH 12.8 (room temperature)
Control of Electroless Copper Plating Take the electroless copper plating solution with the above composition into a beaker (made of Teflon or polypropylene) and heat it to a bath temperature of 7 while blowing air.
2℃, pH 12.4 (72℃, but pH 12 at room temperature)
, 8), and the test specimen was immersed for 10 hours to deposit an electroless copper plating layer with a thickness of 25 to 35 μm in the required circuit area.

The plating bath was automatically controlled using a computer.

(5) Evaluation The following evaluations were performed on the prepared ink, cured product of the ink, and electroless plating test.

The results are shown in Table 3.

Screen printability of fal ink The appearance and resolution of the printed coating film after screen printing using a 300 mesh Tetron screen were visually observed and evaluated on the following three levels.

○: Good △: Slightly poor ×: Poor (bl Gloss and smoothness of resist film The resist film after irradiation with light was visually observed and evaluated on the following three levels.

○: Good △: Slightly poor ×: Poor (C) Surface hardness of resist film The pencil hardness of the resist film after light irradiation was measured.

(dl Adhesion of the resist film) The adhesion of the resist film was measured by a cellophane tape peeling test after a 1 mm width cut.

The number of remaining coating films after the peel test is shown in the numerator.

fe) Acid resistance of resist film The appearance of the resist film after being immersed in a 20% sulfuric acid aqueous solution at 50° C. for 6 hours was visually observed and evaluated on the following three levels.

○: Good △: Slightly poor ×: Poorff) Alkali resistance of resist film After immersion in a 10% sodium hydroxide aqueous solution at 70°C for 10 hours, the appearance was visually observed and evaluated on the following three levels: ○: Good Δ: Slightly poor ×: Poor (g) Solvent resistance of resist film The appearance after immersion in methyl ethyl ketone at 40° C. for 3 hours was visually observed and evaluated on the following three levels.

○: Good △: Slightly poor ×: Poor (hl Solder heat resistance of resist film After flowing in a solder bath at 280° C. for 30 seconds, the appearance was visually observed and evaluated on the following three levels.

○: Good △: Poor gloss ×: Blistering/discoloration (1)
Appearance of resist film after electroless copper plating The appearance of resist film after electroless copper plating was visually observed.

0) Adhesion of resist film after electroless copper plating The adhesion of the resist film was measured by a cellophane tape peeling test after 11 width cuts.

The number of remaining coating films after the peel test is shown in the numerator.

(kl) Contamination of electroless copper plating solution Bubbling of the plating solution during electroless copper plating, presence of floating substances, etc. were visually observed.

(11) Abnormal Plating Deposition Presence or absence of copper plating precipitation on the resist film, presence or absence of unplated parts in the circuit, etc. were visually observed.

(Surface insulation resistance of resist film using a comb-shaped electrode, resist film immediately after curing, moisture resistance test conditions: Resist film after humidity resistance test of C-96/40/95 and after 10 hours immersion in plating solution at 70 ° C. The surface insulation resistance of the resist film was measured at 500V x 1 minute.

(nl Performance of Copper Film) The deposited copper film (thickness: approximately 30 μm) was cut into pieces of 10 mm width x 80 mm length, and a tensile test was conducted at a tensile speed of 2 mm/min to measure the tensile strength and elongation rate.

〔Effect of the invention〕

As shown in Table 4 of the results of the examples, the photocurable resist resin composition for electroless plating of the present invention has a 12% higher resistance to metal plating resist ink than the photocationic resist resin of the prior art. Printability such as thick film resolution and smoothness has been significantly improved, and curability has also been improved, making it possible to use the cured coating in thick films.

It also made it possible to form a resist film with significantly improved electrical properties.

In addition, the resist film shows no contamination to the copper plating solution or abnormal plating precipitation, and its chemical resistance, solvent resistance, solder heat resistance, and other properties are comparable to solder resists and permanent resists. Satisfies the required performance.

Therefore, the resist film has sufficient performance as a resist for electroless plating.

The present invention provides a resist resin composition for photocurable electroless plating, but the resin composition of the present invention is not limited to this use only, and has excellent chemical resistance and solvent resistance. 1. Resists for other circuit formation methods that take advantage of chemical and physical properties such as chemical properties, electrical properties, photosensitive properties, etc. Or applications in metal processing, relief, printing plate materials, various resists in semiconductor manufacturing, protective coatings for circuit boards, electrical and electronic parts, laser discs, paints and coatings for metals, plastics, glass, wood, etc., and other fields. is also possible.

The present invention provides a photocurable resist resin composition, particularly a resist resin composition suitable as a resist ink for electroless plating, and has extremely great industrial significance.

Claims (3)

[Claims] (1) A photocurable resist resin composition for electroless plating containing the following components (A), (B) and (C). (A) (a) At least two polyols selected from the group consisting of polyether polyols, polyester polyols, and polyols having urethane bonds (b) Non-yellowing polyisocyanate (c) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (Here, R is hydrogen or methyl group, R' is carbon number 2~
(meth)acryloyl compound having a number average molecular weight of 500 to 3000 and obtained by reacting the above (a), (b) and (c). Urethane (meth) with an equivalent weight of 200 to 800
Acrylate oligomer, or at least one polyol selected from the group consisting of polyether polyol, polyester polyol, and polyol having a urethane bond, and the above (b) non-yellowing polyisocyanate and (c) acrylic compound are reacted. with a number average molecular weight of 500 to 3000,
and a mixed urethane (meth)acrylate oligomer of at least two types of urethane (meth)acrylate oligomers having a (meth)acryloyl equivalent of 200 to 800 having different polyol components (B) a photocurable compound containing a difunctional acrylic monomer; reactive diluent (C) photopolymerization initiator (2) The mixing ratio of the two types of polyols is polyether polyol/polyester polyol = 9
9 to 40 parts by weight / 1 to 60 parts by weight Polyether polyol / Polyol having urethane bonds = 99 to 40 parts by weight / 1 to 60 parts by weight Polyester polyol / Polyol having urethane bonds = 1 to 60 parts by weight / 99 to 40 The photocurable resist resin composition for electroless plating according to claim (1), which is in parts by weight. (3) Component (A): 100 parts by weight Component (B): 10 to 70 parts by weight Component (C): 0.05 to 10 parts by weight. Photocurable resist resin composition for electroless plating.